Re: crack open a rusted nut with an impact wrench, from one tank of air?

[EMAIL PROTECTED] (Alan Horowitz) wrote in message news:<[EMAIL PROTECTED]>...
> Pardon the fairly wide net of groups I'm posting to; I'm trying to
> catch the guy who knows how to answer this question.....
> 
> Harbor Freight has a 5-gallon, 125-PS  air tank that is small enough
> to be hauled around inside a rolling peice of luggage, which is how I
> would do it in my field-service type of work.
> 
> Can that amount of air, run a impact wrench long enough to crack a
> tough-dog nut to the point where a normal long-handled hand wrench
> would handle it? My experience is that I can do it by hand once it's
> down to 70 foot-pounds of torque. Depending upon how badly placed the
> thing is inside a crowded cabinet, above/below my arm level, etc. But
> let's use 70.
> 
> Given an air tank rated in X gallons @ Y PSI, how do I calculate the
> time it would deliver air at Z psi to an impact wrench at a
> consumption rate of Q cfm, where Z is smaller than Y?   And how much
> power is that, in terms of (let us say) watthours?
> 
> Who sells a flexible drive that is (say) five feet long, and can
> handle the torque required to bust open a rusted nut, if the
> emplacement is such that I can't get a power tool directly onto the
> socket?

Heat + breaker bar + long pipe is what usually works for me.  A good
assortment of swivels and extensions helps if access is difficult.  I
have a good 1/2" impact wrench but with a small compressor it's
worthless.  Electric impact wrench will probably be too weak.
Or take a die or disk grinder to the nut. Unfortunately it always
seems to be a bolt so can't be cut off.